Protecting the British Indian Ocean Territory http://biot.gov.io BIOT’s unique wildlife Fast facts 1. The British Indian Ocean Territory (BIOT) has over 1% of the world’s coral reefs - c.60,000 km2 of shallow limestone platform and coral reefs, which is also the world’s largest contiguous undamaged reef area1. 2. BIOT’s vast coral reefs are composed of five coral atolls, including the mostly submerged Great Chagos Bank, which is the largest atoll structure in the world at some 13,000 km2. 3. Reef fish are six times more abundant in BIOT than on any other reef in the Indian Ocean3. 4. An estimated 10% of all Indian Ocean seamounts are expected to be found in BIOT4. 5. Analyses of pollution levels (1996 and 2006) indicate BIOT belongs ‘to one of the world’s least contaminated coastal areas’5 and ‘could be considered appropriate as a global reference baseline’6. 6. After bleaching in 1998 caused up to 90% mortality of Indian Ocean coral7, BIOT’s reefs ‘recovered more extensively and faster than any other known coral reef system in the Indian Ocean8’, likely due in part to a ‘lack of multiple anthropogenic stresses that most other reef systems endure’9. 7. The critically endangered hawksbill and endangered green turtle, previously exploited in the archipelago, now nest undisturbed throughout the two thirds of the BIOT’s coastline (which is of suitable habitat)10. 8. Diego Garcia is thought to have amongst the highest recorded densities of coconut crab (also of global conservation concern) in the world11 (294 per hectare). 9. Eighteen seabird species breed in BIOT, five in globally important numbers, resulting in ten islands being classified as Important Bird Areas. Diego Garcia qualifies as an internationally important site for birds (Ramsar site) as it holds more than 20,000 waterbirds annually12. 10. Diego Garcia holds one of the Indian Ocean’s largest breeding colonies of red-footed boobies; which has grown from three or four pairs in 1984 to over 5,000 pairs in 2011, with recovery attributable to the low levels of disturbance on the eastern arm of the island 12. 1 Sheppard C. R. C. et al. Reefs and islands of the Chagos Archipelago, Indian Ocean: Why it is 7 Sheppard, C, R, C. Predicted recurrences of mass coral mortality in the Indian Ocean. 2013. the world’s largest no-take marine protected area. Aquat.Conserv.: Mar. Freshwat. Ecosyst . Nature 425, 294-29 22, 233–261 (2012). 8 Gravestock, P and C.Sheppard. 2015. Valuing the ecosystem services of the Chagos: a review 2 Spalding, M.D, C. Ravilious and E.P. Green World Atlas of Coral Reefs. of challenges and estimates. Marine Ecology Progress Series. Vol. 530: 255–270, 2015. 3 Graham, N. A. J., and T.R. McClanahan (2013), ‘The Last Call for Marine Wilderness?’, 9 Graham NAJ, McClanahan TR, MacNeil MA, Wilson SK, Polunin NVC, et al. (2008) Climate BioScience, v. 63, no. 5, pp. 397-402. Warming, Marine Protected Areas and the Ocean-Scale Integrityof Coral Reef Ecosystems. 4 Yesson C, Clark MR, Taylor M, Rogers AD. The global distribution of seamounts based on PLoS ONE 3(8): e3039. doi:10.1371/journal.pone.0003039 30-second bathymetry data. Deep Sea Research Part I: Oceanographic Research Papers. 2011; 10 Mortimer, J.A. and M. Day (1999), ‘Sea turtle populations and habitats in the Chagos 58:442–453 Archipelago’, in Ecology of the Chagos Archipelago (ed. C.R.C. Sheppard & M.R.D. Seaward), 5 Price A.R.G., A. Harris , A. McGowan, A.J. Venkatachalam, & C.R.C. Sheppard (2010), ‘Chagos Linnean Society, p.159 feels the pinch: assessment of holothurian (sea cucumber) abundance, illegal harvesting and 11 Vogt, S. (2004), ‘Coconut Crab (Birgus latro) Survey on Diego Garcia’, in Diego Garcia conservation prospects in British Indian Ocean Territory’, Aquatic Conservation: marine and Integrated Natural Resources Management Plan (September 2005), http://www.zianet.com/ freshwater ecosystems, vol.20:117-126 tedmorris/dg/2005NRMP-Appendixg-coconutcrabsurveys.pdf (accessed 25/11/2016). 6 Guitart C, Sheppard A, Frickers T, Price ARG, Readman JW. 2006. Negligible risks to corals 12 Carr P. Important Bird Areas – the British Indian Ocean Territory. British Birds. 2011b; from antifouling booster biocides and triazine herbicides in coastal waters of the Chagos 104:642–666. archipelago. Marine Pollution Bulletin 54 : 226–246 Contents The British Indian Ocean Territory Marine Protected Area 1 The unique and special BIOT MPA 1 Protecting the BIOT MPA 2 Managing threats to BIOT’s biodiversity 3 Picking up the plastics 3 Fisheries management 4 Understanding and monitoring 5 Restoring habitats 6 How to help 7 1. Black pyramid butterflyfish Eagle rays 1. ©Jon Slayer Blue stripe snapper ©Jon Slayer Mushroom coral The British Indian Ocean Territory Marine Protected Area The unique and special BIOT MPA In 2010, the UK Government created one of the largest Marine Protected Areas on the planet inside the British Indian Ocean Territory, halting commercial fishing across 640,000km2 of the Indian Ocean. This unique and special place is a safe refuge for 310 species of coral, 821 species of fish and 355 species of molluscs, some of which are found nowhere else in the world. Grey reef shark Healthy reefs – the importance of sharks Over 60 species in BIOT are on the International Union for the Conservation of Nature’s (IUCN) ‘red list’ - species which are of global conservation concern. Many of these globally threatened or vulnerable species are sharks. At the top of the food chain, scientists suspect that these beautiful predators play a fundamental role Healthy reef in maintaining healthy coral reefs – for example where black-tip reef sharks are abundant, they may exert a ‘top-down’ pressure on their prey species13, such as emperors and snappers. However, on reefs without sharks, numbers of their prey species, also known as mesopredators (fish in the middle of the food chain), increase. This may seem positive, but scientists have found that where there are less sharks there are also less herbivorous fish14, because the increased numbers of mesopredators consume more smaller fish and their larvae. The Silvertip shark real impact of all of this is felt at the bottom of the food chain where the herbivores, such as parrotfish, maintain coral reef growth by eating algae: without this grazing pressure, newly growing and small corals are vulnerable to being smothered by overgrowth of algae. Although many species of shark are globally threatened, those protected by the BIOT MPA are able to contribute to supporting vibrant and flourishing reefs. Paddle tailParrotfish snapper 13 Papastamatiou, Y.P.; J.E. Caselle; A.M. Friedlander; C.G. Lowe (September 16, 2009). “Distribution, size frequency, and sex ratios of blacktip reef sharks Carcharhinus melanopterus at Palmyra Atoll: a predator-dominated ecosystem”. Journal of Fish Biology. 75 https://pdfs.semanticscholar.org/6e6a/69ada908d31bf59c68237de4e0f80d603db6.pdf 14 Ruppert JLW, Travers MJ, Smith LL, Fortin M-J, Meekan MG (2013) Caught in the Middle: Combined Impacts of Shark Removal and Coral Loss on the Fish Communities of Coral Reefs. PLoS ONE 8(9): e74648. https://doi.org/10.1371/journal.pone.0074648 1 Incredible invertebrates – corals and Feeding the fish clams, worms and snails BIOT is the only place in the Indian Ocean (and Globally, a third of reef-building corals are threatened possibly the world) where populations of red-footed with extinction15 but of the reefs in good condition and brown boobies are increasing. This is evidence in the Indian Ocean, between 25-50% are in BIOT’s of a healthy marine system, as these birds depend waters1. Coral polyps may be amongst BIOT’s smallest on the ocean for food. Perhaps more surprisingly, invertebrates but are also the most important – by recent scientific study in BIOT has revealed that the building a communal skeleton they create the habitat birds also benefit the fish of the coral reef. Around which supports BIOT’s incredible biodiversity, from islands with dense seabird populations, the fish giant clams (another IUCN red-listed species), to the populations are up to 50% higher than those around tiny and colourful Christmas tree worms and the islands without birds, due to the increased levels of enormous gastropod, Triton’s trumpet. This beautiful nutrients (from seabird droppings) seeping off the sea snail keeps reefs healthy by eating crown-of- island and increasing reef productivity16. thorns starfish, which predate corals. Giant clam Great crested terns Christmas tree worms Parrotfish Protecting the MPA Despite BIOT’s isolation, there are still threats to wildlife. The Administration of the British Indian Ocean Territory (BIOTA) seeks to ensure that BIOT can continue to act as a reference site for global conservation efforts and as a natural laboratory, where undisturbed species and habitats can be studied and observed. Working with stakeholders and partners, BIOTA is reducing impacts, undertaking monitoring and working to mitigate such threats. 15 Carpenter K, Abrar M, Aeby G, Aronson RB, Banks S, Bruckner A, Chiriboga A, Cortes J, Delbeel C, De Vantier L, et al. One-third of reef-building Corals face elevated extinction risk from climate change and local impacts. Science. 2008;321:560–563 16 https://www.zsl.org/sites/default/files/media/2016-10/RCUK%202016%20Abstract%20Booklet.pdf 2 Managing threats to BIOT’s biodiversity Picking up the plastics Over 260 million tonnes of plastic is produced every year17, and it is thought about 8 million tonnes18 end up in the world’s oceans annually. Floating plastics are often mistaken for food items particularly by both birds and turtles19. A global 2012 study found that over 30% of seabirds studied had plastic in their digestive system and estimated that by 2050 this will increase to 99% of all bird species20.